A call forwarding service allows a user to forward calls placed to a first telephone number such that the calls are forwarded to a second telephone number. To activate the call forwarding service, a user of the line or device corresponding to the first telephone number typically dials a code, such as “*72,” followed by the second telephone number. A switch or the like in the telephone network detects the activation code dialed by the user and turns on the call forwarding function in the network. Once the call forwarding service is activated, the network routes all calls placed to the first telephone number to the line or device identified by the second telephone number. To de-activate the call forwarding service, the user of the first telephone number dials a code, such as “*73”. Other techniques may be used to turn ON and turn OFF call forwarding, for example, when the user is operating a device not directly associated with the initiating number for which calls are to be forwarded. For a smartphone, an application may configure the phone to do the dialing automatically, in response to simpler selection inputs by the user.
The call forwarding service does not require any authorization during activation, and in particular does not require any authorization from the part of a user of the device that receives calls directed to the second telephone number. A user of the device associated with the second telephone number may thus receive calls forwarded to the second telephone number without wanting to receive such calls. A need therefore exists for a call forwarding system that requires authorization by a party who will receive forwarded calls in order to enable or activate a call forwarding service.